Making wagon sheets out of green tarpaulins. Can it be done?

We've been given three old tarpaulins for the SVR Wagon Department. They're all in reasonable condition (if they were new they wouldn't have been given away), but they are green.
The plan is to get them made to size to use on three GWR open wagons we have got with sheet rails.

The first question is, has anyone got a plan of a GWR wagon sheet? I think I've heard that they were 21' x 14'. Is that right? Knowing the exact size and position of eyelets and lettering would help.

Secondly, what colour were they and how do we colour ours to match? They look about the same shade of grey as the wagons in photos, but then so does everything in B&W photos. Is there a paint that will soak in and colour them permanently? I think I've heard wood preservative mentioned. Any particular brand?

 

If they are a woven material then 'Architectural Solignum' works very well. I have experience of using this in the past on ex-working canal boat sheets.

Andy

 

Send a PM to Faol and I am sure he will be happy to help.

 

That name "Architectural Solignum" rang a bell, so I searched the forum and realised I'm having a senior moment as I'd asked almost the same question over a year ago.
The difference this time though is that we have now got some tarpaulins. I've got some brown Cuprinol Duck's Back at home, so I could try that on one of the tarpaulins and see how it takes.
We could still do with a plan for eyelet and lettering position if anyone's got one please?